package demo;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class HashMapDemo01 {
    public static void main(String[] args) {
        Map<String, String> hashMap = new HashMap<>();

        hashMap.put("username", "湖师张三");
        hashMap.put("address", "湖北黄石");
        hashMap.put("gender", "男");
        hashMap.put("age", "18");

        System.out.println(hashMap);

//        Set<String> keys = hashMap.keySet();
//        for (String key : keys)
    }
}
